They might be called horseflies, but watch out - they’ll happily bite you as well as horses.
Horseflies can give humans, horses, cattle and other large mammals a painful bite, and summer is when they’re likely to attack.
Here’s what you need to know about the pesky varmints:
What do horseflies look like?
Horseflies are black or dark brown, and can range in size from about 10mm to 25mm long.
Horseflies can be found in fields and hedgerows, especially near water, and around stables and cattle.
They tend to be seen in the UK from around May, when adult flies emerge from mud where they’ve grown after hatching, to September and are active during the day, particularly when the sun’s out and highest, around noon.
Horseflies make a low-pitched humming noise when they fly, and aren’t nearly as noisy as mosquitoes, so unfortunately you don't always hear them coming.
Why do horseflies bite?
It’s only female horseflies that suck the blood of mammals. Males are nectar feeders and help with pollination.
Female horseflies cut their victim’s skin with their specially-designed sharp, knife-like mandibles, and then lick the blood. They may even chase you (they want your blood!), and can fly at speeds of up to 15 mph.
What does a horsefly bite look and feel like?
A horsefly bite is a red, itchy, raised and painful bump. It will usually only be painful for a few hours. They can bite through thin layers of clothing too.
What should I do if I'm bitten by a horselfy?
To treat a horsefly bite, cool the area with a wet cold flannel, a cool pack or ice cubes wrapped in a cloth or in a bag. Disinfect the bitten area by cleaning it thoroughly with soap and water, antiseptic wipes or alcohol or vinegar. If the bite’s troubling you, take an antihistamine to reduce itching, or try special after-bite medication available from pharmacies.
Some people are allergic to the bites and may develop a skin rash, hives and wheezing. And watch out for infection, as horseflies move from one host to another, they may carry disease, which is why it’s important to clean and monitor a horsefly bite. If the bitten area stays red and swollen or becomes crusty and yellow, seek medical attention.
The best way to deter horseflies is by using fly spray, and rugs and masks for horses. However, one spray won’t get rid of every type of horsefly.
Have you been troubled by horseflies? Tell us in the Comments section below.